Method for detecting Candida on skin

ABSTRACT

A method and system for rapidly detecting  Candida  on the skin of a host, such as an infant with diaper rash, is provided. The method includes contacting a dermal sample with a colorant that exhibits a certain spectral response (e.g., color change) in the presence of  Candida . For example, the colorant may change from a first color to a second color, from colorless to a color, or from a color to colorless. The colorant is typically capable of differentiating between  Candida  (e.g.,  Candida albicans ) and other microorganisms commonly associated with diaper rash, such as  S. aureus  and  E. coli . Thus, when a dermal sample is placed into contact with the colorant, the color change may simply be observed to determine whether the infection is caused by  Candida . If the color change occurs to a certain extent (e.g., from yellow to bright red), it may be determined that the test sample contains  Candida . Likewise, if a color change occurs to a lesser extent (e.g., from yellow to faint orange) or not at all, it may be determined that the dermal sample contains other microorganisms (e.g.,  S. aureus  or  E. coli ), no infection is present, or that the infection is simply due to other causes. Regardless, it will become readily apparent whether or not treatment for  Candida  is needed.

RELATED APPLICATIONS

The present application is a divisional of U.S. application Ser. No.11/513,500, filed on Aug. 31, 2006, which is incorporated herein in itsentirety by reference thereto.

BACKGROUND OF THE INVENTION

“Diaper rash” (also referred to as diaper dermatitis or incontinentdermatitis) is a common form of irritation and inflammation affectingboth infants and incontinent adults within the skin regions normallycovered by a diaper (e.g., rectal and genital areas). Diaper rash maydevelop when skin is exposed to prolonged contact with urine or feces,which increases skirt pH and contributes to the breakdown of the stratumcorneum. Although diaper rash is usually resolved in a short timeperiod, the skin still becomes susceptible to more serious secondaryinfections once the stratum corneum is damaged. One of the moreproblematic secondary infections associated with diaper rash is “yeastinfection”, which is typically caused by Candida albicans. Under theconditions that result in diaper rash, for instance, the normallyunicellular yeast-like form of Candida albicans can convert into aninvasive, multicellular filamentous form. Candida infection may resultin painful swelling and become difficult to resolve. In severely immunecompromised patients, Candida albicans infection may even spreadthroughout the body and cause systemic infections. It is believed thatsome of the symptoms of Candida infections may be minimized oreliminated with early treatment. Currently, however, no convenientsystem exists for rapidly alerting a caregiver or user of a secondaryCandida infection on the skin.

As such, a need currently exists for a technique of rapidly and simplydetecting the presence of Candida infection on skin.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the present invention, a method fordetecting Candida on the skin of a host is disclosed. The methodcomprises contacting a dermal sample with a colorant that produces avisually observable spectral response (e.g., color change) in thepresence of Candida; detecting the spectral response; and correlatingthe detected spectral response to the presence of Candida in the dermalsample.

In accordance with another embodiment of the present invention, a systemfor detecting a secondary infection associated with diaper rash isdisclosed. The system comprises a solid support applied with a colorant.The colorant produces a first spectral response in the presence ofCandida albicans, a second spectral response in the presence ofStaphylococcus aureus, and a third spectral response in the presence ofEscherichia coli. The first spectral response is visually distinctivefrom the second and third spectral responses.

In accordance with yet another embodiment of the present invention, awipe for detecting a secondary infection associated with diaper rash isdisclosed. The wipe comprises a colorant that produces a first spectralresponse in the presence of Candida albicans, a second spectral responsein the presence of Staphylococcus aureus, and a third spectral responsein the presence of Escherichia coli. The first spectral response isvisually distinctive from the second and third spectral responses.

Other features and aspects of the present invention are discussed ingreater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth more particularly in the remainder of the specification, whichmakes reference to the appended figures in which:

FIG. 1 is a perspective view of an exemplary wipe of the presentinvention before contact with a dermal sample (FIG. 1A) and aftercontact with a sample infected with Candida albicans (FIG. 1B); and

FIG. 2 is a perspective view of another exemplary wipe of the presentinvention before contact with a dermal sample (FIG. 2A); after contactwith a sample infected with Candida albicans (FIG. 2B); and aftercontact with a sample infected with S. aureus or E. coli (FIG. 2C).

Repeat use of reference characters in the present specification anddrawings is intended to represent same or analogous features or elementsof the invention.

DETAILED DESCRIPTION OF REPRESENTATIVE EMBODIMENTS Definitions

As used herein, the term “Candida” refers to a genus of the Fungikingdom that includes, for instance, the species Candida albicans,Candida dubliniensis, Candida glabrata, Candida guilliermondii, Candidakefyr, Candida krusei, Candida lusitaniae, Candida parapsilosis, Candidatropicalis, and Candida utilis.

As used herein, the term “dermal sample” generally refers to the skin ofa host (e.g., any animal, preferably a human) and/or a biologicalmaterial obtained directly and/or indirectly from the skin, such as fromdischarge, tissue, etc. The test sample may optionally be pretreatedbefore testing, such as by filtration, precipitation, dilution,distillation, mixing, concentration, inactivation of interferingcomponents, the addition of reagents, lysing, etc.

As used herein the term “nonwoven web” generally refers to a web havinga structure of individual fibers or threads which are interlaid, but notin an identifiable manner as in a knitted fabric. Examples of suitablenonwoven webs include, but are not limited to, meltblown webs, spunbondwebs, carded webs, airlaid webs, etc. The basis weight of the nonwovenweb may vary, such as from about 5 grams per square meter (“gsm”) to 120gsm, in some embodiments from about 10 gsm to about 70 gsm, and in someembodiments, from about 15 gsm to about 35 gsm.

As used herein, the term “meltblown web” generally refers to a nonwovenweb that is formed by a process in which a molten thermoplastic materialis extruded through a plurality of fine, usually circular, diecapillaries as molten fibers into converging high velocity gas (e.g.air) streams that attenuate the fibers of molten thermoplastic materialto reduce their diameter, which may be to microfiber diameter.Thereafter, the meltblown fibers are carried by the high velocity gasstream and are deposited on a collecting surface to form a web ofrandomly dispersed meltblown fibers. Such a process is disclosed, forexample, in U.S. Pat. No. 3,849,241 to Butin, et al., which isincorporated herein in its entirety by reference thereto for allpurposes. Generally speaking, meltblown fibers may be microfibers thatare substantially continuous or discontinuous, generally smaller than 10microns in diameter, and generally tacky when deposited onto acollecting surface.

As used herein, the term “spunbond web” generally refers to a webcontaining small diameter substantially continuous fibers. The fibersare formed by extruding a molten thermoplastic material from a pluralityof fine, usually circular, capillaries of a spinnerette with thediameter of the extruded fibers then being rapidly reduced as by, forexample, eductive drawing and/or other well-known spunbondingmechanisms. The production of spunbond webs is described andillustrated, for example, in U.S. Pat. Nos. 4,340,563 to Appel, et al.,3,692,618 to Dorschner, et al., 3,802,817 to Matsuki, et al., 3,338,992to Kinney, 3,341,394 to Kinney, 3,502,763 to Hartman, 3,502,538 to Levy,3,542,615 to Dobo, et al., and 5,382,400 to Pike, et al., which areincorporated herein in their entirety by reference thereto for allpurposes. Spunbond fibers are generally not tacky when they aredeposited onto a collecting surface. Spunbond fibers may sometimes havediameters less than about 40 microns, and are often between about 5 toabout 20 microns.

As used herein, the term “carded web” refers to a web made from staplefibers that are sent through a combing or carding unit, which separatesor breaks apart and aligns the staple fibers in the machine direction toform a generally machine direction-oriented fibrous nonwoven web. Suchfibers are usually obtained in bales and placed in an opener/blender orpicker, which separates the fibers prior to the carding unit. Onceformed, the web may then be bonded by one or more known methods.

As used herein, the term “airlaid web” refers to a web made from bundlesof fibers having typical lengths ranging from about 3 to about 19millimeters (mm). The fibers are separated, entrained in an air supply,and then deposited onto a forming surface, usually with the assistanceof a vacuum supply. Once formed, the web is then bonded by one or moreknown methods.

Detailed Description

Reference now will be made in detail to various embodiments of theinvention, one or more examples of which are set forth below. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations may be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment, may be used on another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

Generally speaking, the present invention is directed to a method andsystem for rapidly detecting Candida on the skin of a host, such as aninfant with diaper rash. The method includes contacting a dermal samplewith a colorant that exhibits a certain spectral response (e.g., colorchange) in the presence of Candida. For example, the colorant may changefrom a first color to a second color, from colorless to a color, or froma color to colorless. The colorant is typically capable ofdifferentiating between Candida (e.g., Candida albicans) and othermicroorganisms commonly associated with diaper rash, such as S. aureusand E. coli. Thus, when a dermal sample is placed into contact with thecolorant, the color change may simply be observed to determine whetherthe infection is caused by Candida. If the color change occurs to acertain extent (e.g., from yellow to bright red), it may be determinedthat the test sample contains Candida. Likewise, if a color changeoccurs to a lesser extent (e.g., from yellow to faint orange) or not atall, it may be determined that the dermal sample contains othermicroorganisms (e.g., S. aureus or E. coli), no infection is present, orthat the infection is simply due to other causes. Regardless, it willbecome readily apparent whether or not treatment for Candida is needed.

One particularly suitable class of colorants that may undergo adetectable color change in the presence of Candida is pH-sensitivecolorants. Namely, pH-sensitive colorants can detect a change in the pHof the growth medium of the microorganism. Because the acidic/basicshift may vary for different microorganisms, pH-sensitive colorants maybe selected that are tuned for the desired pH transition. CertainCandida species (e.g., Candida albicans) for instance, are believed toproduce metabolites or other byproducts that alter the pH of the growthmedium to about 6.6. Thus, pH-sensitive colorants that undergo a changein pH at or near this level may be used in the present invention. PhenolRed (i.e., phenolsulfonephthalein), for example, may be particularlysuitable in that it exhibits a transition from yellow to red over a pHrange of about 6.6 to 8.0.

Other phthalein colorants, however, may also be used in the presentinvention to indicate the presence of Candida. Derivatives of PhenolRed, for instance, may be employed, such as those substituted withchloro, bromo, methyl, sodium carboxylate, carboxylic acid, hydroxyl andamine functional groups. Exemplary substituted Phenol Red compoundsinclude, for instance, Chlorophenol Red, Metacresol Purple(meta-cresolsulfonephthalein), Cresol Red(ortho-cresolsulfonephthalein), Pyrocatecol Violet(pyrocatecolsulfonephthalein), Chlorophenol Red(3′,3″-dichlorophenolsulfonephthalein), Xylenol Blue (the sodium salt ofpara-xylenolsulfonephthalein), Xylenol Orange, Mordant Blue 3 (C.I.43820), 3,4,5,6-tetrabromophenolsulfonephthalein, Bromoxylenol Blue,Bromophenol Blue (3′,3″, 5′,5″-tetrabromophenolsulfonephthalein),Bromochlorophenol Blue (the sodium salt ofdibromo-5′,5″-dichlorophenolsulfonephthalein), Bromocresol Purple(5′,5″-dibromo-ortho-cresolsulfonephthalein), Bromocresol Green (3′,3″,5′,5″-tetrabromo-ortho-cresolsulfonephthalein), and so forth. Stillother suitable phthalein colorants are well known in the art, and mayinclude Bromothymol Blue, Thymol Blue, Bromocresol Purple,thymolphthalein, and phenolphthalein (a common component of universalindicators). For example, Chlorophenol Red exhibits a transition fromyellow to red over a pH range of about 4.8 to 6.4; Bromothymol Blueexhibits a transition from yellow to blue over a pH range of about 6.0to 7.6; thymolphthalein exhibits a transition from colorless to blueover a pH range of about 9.4 to 10.6; phenolphthalein exhibits atransition from colorless to pink over a pH range of about 8.2 to 10.0;Thymol Blue exhibits a first transition from red to yellow over a pHrange of about 1.2 to 2.8 and a second transition from yellow to pH overa pH range of 8.0 to 9.6; Bromophenol Blue exhibits a transition fromyellow to violet over a pH range of about 3.0 to 4.6; Bromocresol Greenexhibits a transition from yellow to blue over a pH range of about 3.8to 5.4; and Bromocresol Purple exhibits a transition from yellow toviolet over a pH of about 5.2 to 6.8.

Hydroxyanthraquinones constitute another suitable class of pH-sensitivecolorants for use in the present invention. Hydroxyanthraquinones havethe following general structure:

The numbers 1-8 shown in the general formula represent a location on thefused ring structure at which substitution of a functional group mayoccur. For hydroxyanthraquinones, at least one of the functional groupsis or contains a hydroxy (—OH) group. Other examples of functionalgroups that may be substituted on the fused ring structure includehalogen groups (e.g., chlorine or bromine groups), sulfonyl groups(e.g., sulfonic acid salts), alkyl groups, benzyl groups, amino groups(e.g., primary, secondary, tertiary, or quaternary amines), carboxygroups, cyano groups, phosphorous groups, etc. Some suitablehydroxyanthraquinones that may be used in the present invention, MordantRed 11 (Alizarin), Mordant Red 3 (Alizarin Red S), Alizarin Yellow R,Alizarin Complexone, Mordant Black 13 (Alizarin Blue Black B), MordantViolet 5 (Alizarin Violet 3R), Alizarin Yellow GG, Natural Red 4(carminic acid), amino-4-hydroxyanthraquinone, Emodin, Nuclear Fast Red,Natural Red 16 (Purpurin), Quinalizarin, and so forth. For instance,carminic acid exhibits a first transition from orange to red over a pHrange of about 3.0 to 5.5 and a second transition from red to purpleover a pH range of about 5.5 to 7.0. Alizarin Yellow R, on the otherhand, exhibits a transition from yellow to orange-red over a pH range ofabout 10.1 to 12.0.

Yet another suitable class of pH-sensitive colorants that may beemployed is aromatic azo compounds having the general structure:X—R₁—N═N—R₂—Y

wherein,

R₁ is an aromatic group;

R₂ is selected from the group consisting of aliphatic and aromaticgroups; and

X and Y are independently selected from the group consisting ofhydrogen, halides, —NO₂, —NH₂, aryl groups, alkyl groups, alkoxy groups,sulfonate groups, —SO₃H, —OH, —COH, —COOH, halides, etc. Also suitableare azo derivatives, such as azoxy compounds (X—R₁—N═NO—R₂—Y) or hydrazocompounds (X—R₁—NH—NH—R₂—Y). Particular examples of such azo compounds(or derivatives thereof) include Methyl Violet, Methyl Yellow, MethylOrange, Methyl Red, and Methyl Green. For instance, Methyl Violetundergoes a transition from yellow to blue-violet at a pH range of about0 to 1.6, Methyl Yellow undergoes a transition from red to yellow at apH range of about 2.9 to 4.0, Methyl Orange undergoes a transition fromred to yellow at a pH range of about 3.1 to 4.4, and Methyl Redundergoes a transition from red to yellow at a pH range of about 4.2 to6.3.

Arylmethanes (e.g., diarylmethanes and triarylmethanes) constitute stillanother class of suitable pH-sensitive colorants for use in the presentinvention. Triarylmethane leuco bases, for example, have the followinggeneral structure:

wherein R, R′, and R″ are independently selected from substituted andunsubstituted aryl groups, such as phenyl, naphthyl, anthracenyl, etc.The aryl groups may be substituted with functional groups, such asamino, hydroxyl, carbonyl, carboxyl, sulfonic, alkyl, and/or other knownfunctional groups. Examples of such triarylmethane leuco bases includeLeucomalachite Green, Pararosaniline Base, Crystal Violet Lactone,Crystal Violet Leuco, Crystal Violet, CI Basic Violet 1, CI Basic Violet2, CI Basic Blue, CI Victoria Blue, N-benzoyl leuco-methylene, etc.Likewise suitable diarylmethane leuco bases may include 4,4′-bis(dimethylamino) benzhydrol (also known as “Michler's hydrol”), Michler'shydrol leucobenzotriazole, Michler's hydrol leucomorpholine, Michler'shydrol leucobenzenesulfonamide, etc. In one particular embodiment, thecolorant is Leucomalachite Green Carbinol (Solvent Green 1) or an analogthereof, which is normally colorless and has the following structure:

Under acidic conditions, one or more free amino groups of theLeucomalachite Green Carbinol form may be protonated to form MalachiteGreen (also known as Aniline Green, Basic Green 4, Diamond Green B, orVictoria Green B), which has the following structure:

Malachite Green typically exhibits a transition from yellow toblue-green over a pH range 0.2 to 1.8. Above a pH of about 1.8,malachite green turns a deep green color.

Still other suitable pH-sensitive colorants that may be employed includeCongo Red, Litmus (azolitmin), Methylene Blue, Neutral Red, AcidFuchsin, Indigo Carmine, Brilliant Green, Picric acid, Metanil Yellow,m-Cresol Purple, Quinaldine Red, Tropaeolin OO, 2,6-dinitrophenol,Phloxine B, 2,4-dinitrophenol, 4-dimethylaminoazobenzene,2,5-dinitrophenol, 1-Naphthyl Red, Chlorophenol Red, Hematoxylin,4-nitrophenol, nitrazine yellow, 3-nitrophenol, Alkali Blue, EpsilonBlue, Nile Blue A, universal indicators, and so forth. For instance,Congo Red undergoes a transition from blue to red at a pH range of about3.0 to 5.2, Litmus undergoes a transition from red to blue at a pH rangeof about 4.5 to 8.3, and Neutral Red undergoes a transition from red toyellow at a pH range of about 11.4 to 13.0.

In addition to pH, other mechanisms may also be wholly or partiallyresponsible for inducing a color change in the colorant. For example,Candida may produce low molecular weight iron-complexing compounds ingrowth media, which are known as “siderophores.” Metal complexingcolorants may thus be employed in some embodiments of the presentinvention that undergo a color change in the presence of siderophores.One particularly suitable class of metal complexing colorants arearomatic azo compounds, such as Eriochrome Black T, Eriochrome Blue SE,Eriochrome Blue Black B, Eriochrome Cyanine R, Xylenol Orange, ChromeAzurol S, carminic acid, etc. Still other suitable metal complexingcolorants may include Alizarin Complexone, Alizarin S, Arsenazo III,Aurintricarboxylic acid, 2,2′-Bipyidine, Bromopyrogallol Red, Calcon(Eriochrom Blue Black R), Calconcarboxylic acid, Chromotropic acid,disodium salt, Cuprizone, 5-(4-Dimethylamino-benzylidene)rhodanine,Dimethylglyoxime, 1,5-Diphenylcarbazide, Dithizone, FluoresceinComplexone, Hematoxylin, 8-Hydroxyquinoline, 2-Mercaptobenzothiazole,Methylthymol Blue, Murexide, 1-Nitroso-2-naphthol, 2-Nitroso-1-naphthol,Nitroso-R-salt, 1,10-Phenanthroline, Phenylfluorone, Phthalein Purple,1-(2-Pyridylazo)-naphthol, 4-(2-Pyridylazo)resorcinol, Pyrogallol Red,Sulfonazo III, 5-Sulfosalicylic acid, 4-(2-Thiazolylazo)resorcinol,Thorin, Thymolthalexon, Tiron, Tolurnr-3,4-dithiol, Zincon, and soforth. It should be noted that one or more of the pH-sensitive colorantsreferenced above may also be classified as metal complexing colorants.

Although the above-referenced colorants are classified based on theirmechanism of color change (e.g., pH sensitive, metal complexing, etc.),it should be understood that the present invention is not limited to anyparticular mechanism for the color change. Even when a pH-sensitivecolorant is employed, for instance, other mechanisms may actually bewholly or partially responsible for the color change of the colorant.For example, redox reactions between the colorant and microorganism maycontribute to the color change.

As stated above, colorants may be employed in the present invention thatdifferentiate between the presence of Candida and other microorganismscommonly associated with diaper rash, such as E. coli and S. aureus.However, the method is by no means limited to the detection of Candida.In fact, additional colorants may also be employed in the presentinvention that are capable of detecting the presence of othermicroorganisms, such as bacteria. Several relevant bacterial groups thatmay be detected in the present invention include, for instance, gramnegative rods (e.g., Entereobacteria); gram negative curved rods (e.g.,vibious, Heliobacter, Campylobacter, etc.); gram negative cocci (e.g.,Neisseria); gram positive rods (e.g., Bacillus, Clostridium, etc.); grampositive cocci (e.g., Staphylococcus, Streptococcus, etc.); obligateintracellular parasites (e.g., Ricckettsia and Chlamydia); acid fastrods (e.g., Myobacterium, Nocardia, etc.); spirochetes (e.g., Treponema,Borellia, etc.); and mycoplasmas (i.e., tiny bacteria that lack a cellwall). Particularly relevant bacteria include E. coli (gram negativerod), Klebsiella pneumonia (gram negative rod), Streptococcus (grampositive cocci), Salmonella choleraesuis (gram negative rod),Staphyloccus aureus (gram positive cocci), and P. aeruginosa (gramnegative rod).

The colorants employed for detecting bacteria may be capable ofindependently differentiating bacteria, or simply provide a color changeindicative of the presence of a broad spectrum of bacteria.Solvatochromatic colorants, for instance, are believed to exhibit adetectable color change in the presence of a broad spectrum of bacteria.Although solvatochromatic colorants may also undergo a color change inthe presence of Candida microorganisms, it is generally believed to beto a lesser extent. Various suitable solvatochromatic colorants that aresuitable for use in the present invention are described in U.S. PatentApplication Publication No. 2006/0134728 to MacDonald, et al., which isincorporated herein in its entirety by reference thereto for allpurposes. For example, merocyanine colorants (e.g., mono-, di-, andtri-merocyanines) are one example of a type of solvatochromatic colorantthat may be employed in the present invention. Merocyanine colorants,such as merocyanine 540, fall within the donor-simple acceptor colorantclassification of Griffiths as discussed in “Colour and Constitution ofOrganic Molecules” Academic Press, London (1976). More specifically,merocyanine colorants have a basic nucleus and acidic nucleus separatedby a conjugated chain having an even number of methine carbons. Suchcolorants possess a carbonyl group that acts as an electron acceptormoiety. The electron acceptor is conjugated to an electron donatinggroup, such as a hydroxyl or amino group. The merocyanine colorants maybe cyclic or acyclic (e.g., vinylalogous amides of cyclic merocyaninecolorants).

Other suitable solvatochromatic colorants that may be used in thepresent invention include those that possess a permanent zwitterionicform. That is, these colorants have formal positive and negative chargescontained within a contiguous π-electron system. Contrary to themerocyanine colorants referenced above, a neutral resonance structurecannot be drawn for such permanent zwitterionic colorants. Exemplarycolorants of this class include N-phenolate betaine colorants, such asthose having the following general structure:

wherein R₁-R₅ are independently selected from the group consisting ofhydrogen, a nitro group (e.g., nitrogen), a halogen, or a linear,branched, or cyclic C₁ to C₂₀ group (e.g., alkyl, phenyl, aryl,pyridinyl, etc.), which may be saturated or unsaturated andunsubstituted or optionally substituted at the same or at differentcarbon atoms with one, two or more halogen, nitro, cyano, hydroxy,alkoxy, amino, phenyl, aryl, pyridinyl, or alkylamino groups. Forexample, the N-phenolate betaine colorant may be4-(2,4,6-triphenylpyridinium-1-yl)-2,6-diphenylphenolate (Reichardt'sdye) having the following general structure:

Reichardt's dye shows strong negative solvatochromism and may thusundergo a significant color change from blue to colorless in thepresence of bacteria. That is, Reichardt's dye displays a shift inabsorbance to a shorter wavelength and thus has visible color changes assolvent eluent strength (polarity) increases.

Regardless of the type employed, a colorant is generally applied to asolid support for subsequent contact with a dermal sample. The nature ofthe solid support may vary depending on the intended use, and mayinclude materials such as films, paper, nonwoven webs, knitted fabrics,woven fabrics, foam, glass, etc. Desirably, the solid support is a wipeconfigured for use on skin, such as a baby wipe, adult wipe, hand wipe,face wipe, cosmetic wipe, household wipe, industrial wipe, personalcleansing wipe, cotton ball, cotton-tipped swab, and so forth. In thismanner, the colorant may provide information about the presence ofmicroorganisms in a dermal sample during and/or shortly after the normaluse of the wipe. For example, the colorant may be present on a baby wipeto provide the caregiver with a rapid indication of whether amicroorganism is present on the skin of a baby.

The wipe may be formed from any of a variety of materials as is wellknown in the art. For example, the wipe may include a nonwoven web thatcontains an absorbent material of sufficient wet strength and absorbencyfor use in the desired application. For example, the nonwoven web mayinclude absorbent fibers formed by a variety of pulping processes, suchas kraft pulp, sulfite pulp, thermomechanical pulp, etc. The pulp fibersmay include softwood fibers having an average fiber length of greaterthan 1 mm and particularly from about 2 to 5 mm based on alength-weighted average. Such softwood fibers can include, but are notlimited to, northern softwood, southern softwood, redwood, red cedar,hemlock, pine (e.g., southern pines), spruce (e.g., black spruce),combinations thereof, and so forth. Exemplary commercially availablepulp fibers suitable for the present invention include those availablefrom Kimberly-Clark Corporation under the trade designations“Longlac-19.” Hardwood fibers, such as eucalyptus, maple, birch, aspen,and so forth, can also be used. In certain instances, eucalyptus fibersmay be particularly desired to increase the softness of the web.Eucalyptus fibers can also enhance the brightness, increase the opacity,and change the pore structure of the web to increase its wickingability. Moreover, if desired, secondary fibers obtained from recycledmaterials may be used, such as fiber pulp from sources such as, forexample, newsprint, reclaimed paperboard, and office waste. Further,other absorbent fibers that may be used in the present invention, suchas abaca, sabai grass, milkweed floss, pineapple leaf, cellulosicesters, cellulosic ethers, cellulosic nitrates, cellulosic acetates,cellulosic acetate butyrates, ethyl cellulose, regenerated celluloses(e.g., viscose or rayon), and so forth.

Synthetic thermoplastic fibers may also be employed in the nonwoven web,such as those formed from polyolefins, e.g., polyethylene,polypropylene, polybutylene, etc.; polytetrafluoroethylene; polyesters,e.g., polyethylene terephthalate and so forth; polyvinyl acetate;polyvinyl chloride acetate; polyvinyl butyral; acrylic resins, e.g.,polyacrylate, polymethylacrylate, polymethylmethacrylate, and so forth;polyamides, e.g., nylon; polyvinyl chloride; polyvinylidene chloride;polystyrene; polyvinyl alcohol; polyurethanes; polylactic acid;copolymers thereof; and so forth. Because many synthetic thermoplasticfibers are inherently hydrophobic (i.e., non-wettable), such fibers mayoptionally be rendered more hydrophilic (i.e., wettable) by treatmentwith a surfactant solution before, during, and/or after web formation.Other known methods for increasing wettability may also be employed,such as described in U.S. Pat. No. 5,057,361 to Sayovitz, et al., whichis incorporated herein in its entirety by reference thereto for allpurposes.

If desired, the nonwoven web material may be a composite that contains acombination of synthetic thermoplastic polymer fibers and absorbentfibers, such as polypropylene and pulp fibers. The relative percentagesof such fibers may vary over a wide range depending on the desiredcharacteristics of the nonwoven composite. For example, the nonwovencomposite may contain from about 1 wt. % to about 60 wt. %, in someembodiments from 5 wt. % to about 50 wt. %, and in some embodiments,from about 10 wt. % to about 40 wt. % synthetic polymeric fibers. Thenonwoven composite may likewise contain from about 40 wt. % to about 99wt. %, in some embodiments from 50 wt. % to about 95 wt. %, and in someembodiments, from about 60 wt. % to about 90 wt. % absorbent fibers.

Nonwoven composites may be formed using a variety of known techniques.For example, the nonwoven composite may be a “coform material” thatcontains a mixture or stabilized matrix of thermoplastic fibers and asecond non-thermoplastic material. As an example, coform materials maybe made by a process in which at least one meltblown die head isarranged near a chute through which other materials are added to the webwhile it is forming. Such other materials may include, but are notlimited to, fibrous organic materials such as woody or non-woody pulpsuch as cotton, rayon, recycled paper, pulp fluff and alsosuperabsorbent particles, inorganic and/or organic absorbent materials,treated polymeric staple fibers and so forth. Some examples of suchcoform materials are disclosed in U.S. Pat. Nos. 4,100,324 to Anderson,et al.; 5,284,703 to Everhart, et al.; and 5,350,624 to Georger, at al.;which are incorporated herein in their entirety by reference thereto forall purposes. Alternatively, the nonwoven composite may be formed beformed by hydraulically entangling fibers and/or filaments withhigh-pressure jet streams of water. Hydraulically entangled nonwovencomposites of staple length fibers and continuous filaments aredisclosed, for example, in U.S. Pat. Nos. 3,494,821 to Evans and4,144,370 to Bouolton, which are incorporated herein in their entiretyby reference thereto for all purposes. Hydraulically entangled nonwovencomposites of a continuous filament nonwoven web and pulp fibers aredisclosed, for example, in U.S. Pat. Nos. 5,284,703 to Everhart, et al.and 6,315,864 to Anderson, at al., which are incorporated herein intheir entirety by reference thereto for all purposes.

Regardless of the materials or processes utilized to form the wipe, thebasis weight of the wipe is typically from about 20 to about 200 gramsper square meter (gsm), and in some embodiments, between about 35 toabout 100 gsm. Lower basis weight products may be particularly wellsuited for use as light duty wipes, while higher basis weight productsmay be better adapted for use as industrial wipes.

The wipe may assume a variety of shapes, including but not limited to,generally circular, oval, square, rectangular, or irregularly shaped.Each individual wipe may be arranged in a folded configuration andstacked one on top of the other to provide a stack of wet wipes. Suchfolded configurations are well known to those skilled in the art andinclude c-folded, z-folded, quarter-folded configurations and so forth.For example, the wipe may have an unfolded length of from about 2.0 toabout 80.0 centimeters, and in some embodiments, from about 10.0 toabout 25.0 centimeters. The wipes may likewise have an unfolded width offrom about 2.0 to about 80.0 centimeters, and in some embodiments, fromabout 10.0 to about 25.0 centimeters. The stack of folded wipes may beplaced in the interior of a container, such as a plastic tub, to providea package of wipes for eventual sale to the consumer. Alternatively, thewipes may include a continuous strip of material which has perforationsbetween each wipe and which may be arranged in a stack or wound into aroll for dispensing. Various suitable dispensers, containers, andsystems for delivering wipes are described in U.S. Pat. Nos. 5,785,179to Buczwinski, et al.; 5,964,351 to Zander; 6,030,331 to Zander;6,158,614 to Haynes, et al.; 6,269,969 to Huang, et al.; 6,269,970 toHuang, et al.; and 6,273,359 to Newman, et al., which are incorporatedherein in their entirety by reference thereto for all purposes.

In certain embodiments of the present invention, the wipe is a “wetwipe” in that it contains a solution for cleaning, disinfecting,sanitizing, etc. The particular wet wipe solutions are not critical andare described in more detail in U.S. Pat. Nos. 6,440,437 to Krzysik, etal.; 6,028,018 to Amundson, et al.; 5,888,524 to Cole; 5,667,635 to Win,et al.; and 5,540,332 to Kopacz, et al., which are incorporated hereinin their entirety by reference thereto for all purposes. The amount ofthe wet wipe solution employed may depending upon the type of wipematerial utilized, the type of container used to store the wipes, thenature of the cleaning formulation, and the desired end use of thewipes. Generally, each wipe contains from about 150 to about 600 wt. %and desirably from about 300 to about 500 wt. % of a wet wipe solutionbased on the dry weight of the wipe.

Typically, the colorant of the present invention is applied to a wipe orother solid support in the form of a composition that contains a mobilecarrier. The carrier may be a liquid, gas, gel, etc., and may beselected to provide the desired performance (time for change of color,contrast between different areas, and sensitivity) of the colorant. Insome embodiments, for instance, the carrier may be an aqueous solvent,such as water, as well as a non-aqueous solvent, such as glycols (e.g.,propylene glycol, butylene glycol, triethylene glycol, hexylene glycol,polyethylene glycols, ethoxydiglycol, and dipropyleneglycol); alcohols(e.g., methanol, ethanol, n-propanol, and isopropanol); triglycerides;ethyl acetate; acetone; triacetin; acetonitrile, tetrahydrafuran;xylenes; formaldehydes (e.g., dimethylformamide, “DMF”); etc. Suitabletechniques for applying the colorant composition to the solid supportinclude printing, dipping, spraying, melt extruding, coating (e.g.,solvent coating, powder coating, brush coating, etc.), and so forth.Upon application, the colorant composition may be dried to remove thecarrier and leave a residue of the colorant for interacting with amicroorganism.

Other additives may also be employed, either separately or inconjunction with a colorant composition. In one embodiment, forinstance, cyclodextrins are employed that enhance the sensitivity andcontrast of a colorant. While not wishing to be bound by theory, thepresent inventors believe that such additives may inhibit thecrystallization of the colorant and thus provide a more vivid color andalso enhance detection sensitivity. That is, single colorant moleculeshave greater sensitivity for microorganisms because each colorantmolecule is free to interact with the microbial membrane. In contrast,small crystals of colorant have to first dissolve and then penetrate themembrane. Examples of suitable cyclodextrins may include, but are notlimited to, hydroxypropyl-β-cyclodextrin, hydroxyethyl-β-cyclodextrin,γ-cyclodextrin, hydroxypropyl-γ-cyclodextrin, andhydroxyethyl-γ-cyclodextrin, which are commercially available fromCerestar International of Hammond, Ind.

Surfactants may also help enhance the sensitivity and contrast providedby the colorant. Particularly desired surfactants are nonionicsurfactants, such as ethoxylated alkylphenols, ethoxylated andpropoxylated fatty alcohols, ethylene oxide-propylene oxide blockcopolymers, ethoxylated esters of fatty (C₈-C₁₈) acids, condensationproducts of ethylene oxide with long chain amines or amides,condensation products of ethylene oxide with alcohols, acetylenic diols,and mixtures thereof. Various specific examples of suitable nonionicsurfactants include, but are not limited to, methyl gluceth-10, PEG-20methyl glucose distearate, PEG-20 methyl glucose sesquistearate, C₁₁-C₁₅pareth-20, ceteth-8, ceteth-12, dodoxynol-12, laureth-15, PEG-20 castoroil, polysorbate 20, steareth-20, polyoxyethylene-10 cetyl ether,polyoxyethylene-10 stearyl ether, polyoxyethylene-20 cetyl ether,polyoxyethylene-10 oleyl ether, polyoxyethylene-20 oleyl ether, anethoxylated nonylphenol, ethoxylated octylphenol, ethoxylateddodecylphenol, or ethoxylated fatty (C₆-C₂₂) alcohol, including 3 to 20ethylene oxide moieties, polyoxyethylene-20 isohexadecyl ether,polyoxyethylene-23 glycerol laurate, polyoxy-ethylene-20 glycerylstearate, PPG-10 methyl glucose ether, PPG-20 methyl glucose ether,polyoxyethylene-20 sorbitan monoesters, polyoxyethylene-80 castor oil,polyoxyethylene-15 tridecyl ether, polyoxy-ethylene-6 tridecyl ether,laureth-2, laureth-3, laureth-4, PEG-3 castor oil, PEG 600 dioleate, PEG400 dioleate, and mixtures thereof. Commercially available nonionicsurfactants may include the SURFYNOL® range of acetylenic diolsurfactants available from Air Products and Chemicals of Allentown, Pa.and the TWEEN® range of polyoxyethylene surfactants available fromFischer Scientific of Pittsburgh, Pa.

A binder may also be employed to facilitate the immobilization of thecolorant on the wipe or other solid support. For example, water-solubleorganic polymers may be employed as binders, such as polysaccharides andderivatives thereof. Polysaccharides are polymers containing repeatedcarbohydrate units, which may be cationic, anionic, nonionic, and/oramphoteric. In one particular embodiment, the polysaccharide is anonionic, cationic, anionic, and/or amphoteric cellulosic ether.Suitable nonionic cellulosic ethers may include, but are not limited to,alkyl cellulose ethers, such as methyl cellulose and ethyl cellulose;hydroxyalkyl cellulose ethers, such as hydroxyethyl cellulose,hydroxypropyl cellulose, hydroxypropyl hydroxybutyl cellulose,hydroxyethyl hydroxypropyl cellulose, hydroxyethyl hydroxybutylcellulose and hydroxyethyl hydroxypropyl hydroxybutyl cellulose; alkylhydroxyalkyl cellulose ethers, such as methyl hydroxyethyl cellulose,methyl hydroxypropyl cellulose, ethyl hydroxyethyl cellulose, ethylhydroxypropyl cellulose, methyl ethyl hydroxyethyl cellulose and methylethyl hydroxypropyl cellulose; and so forth.

The colorant composition may be applied to all or only a portion of thewiper or other solid support. Suitable techniques for applying thecolorant composition to the solid support include printing, dipping,spraying, melt extruding, coating (e.g., solvent coating, powdercoating, brush coating, etc.), spraying, and so forth. In oneembodiment, for example, the colorant composition is printed onto thesupport (e.g., wipe), such as in the form of indicia that conveys acertain message to the user.

A variety of printing techniques may be used for applying the colorantcomposition to the support, such as gravure printing, flexographicprinting, screen printing, laser printing, thermal ribbon printing,piston printing, etc. In one particular embodiment, ink-jet printingtechniques are employed to apply the colorant composition to thesupport. Ink-jet printing is a non-contact printing technique thatinvolves forcing an ink through a tiny nozzle (or a series of nozzles)to form droplets that are directed toward the support. Two techniquesare generally utilized, i.e., “DOD” (Drop-On-Demand) or “continuous”ink-jet printing. In continuous systems, ink is emitted in a continuousstream under pressure through at least one orifice or nozzle. The streamis perturbed by a pressurization actuator to break the stream intodroplets at a fixed distance from the orifice. DOD systems, on the otherhand, use a pressurization actuator at each orifice to break the inkinto droplets. The pressurization actuator in each system may be apiezoelectric crystal, an acoustic device, a thermal device, etc. Theselection of the type of ink jet system varies on the type of materialto be printed from the print head. For example, conductive materials aresometimes required for continuous systems because the droplets aredeflected electrostatically. Thus, when the sample channel is formedfrom a dielectric material, DOD printing techniques may be moredesirable.

The colorant composition may be formed as a printing ink using any of avariety of known components and/or methods. For example, the printingink may contain water as a carrier, and particularly deionized water.Various co-carriers may also be included in the ink, such as lactam,N-methylpyrrolidone, N-methylacetamide, N-methylmorpholine-N-oxide,N,N-dimethylacetamide, N-methyl formamide,propyleneglycol-monomethylether, tetramethylene sulfone,tripropyleneglycolmonomethylether, propylene glycol, and triethanolamine(TEA). Humectants may also be utilized, such as ethylene glycol;diethylene glycol; glycerine; polyethylene glycol 200, 300, 400, and600; propane 1,3 diol; propylene-glycolmonomethyl ethers, such asDowanol PM (Gallade Chemical Inc., Santa Ana, Calif.); polyhydricalcohols; or combinations thereof. Other additives may also be includedto improve ink performance, such as a chelating agent to sequester metalions that could become involved in chemical reactions over time, acorrosion inhibitor to help protect metal components of the printer orink delivery system, and a surfactant to adjust the ink surface tension.Various other components for use in an ink, such as colorantstabilizers, photoinitiators, binders, surfactants, electrolytic salts,pH adjusters, etc., may be employed as described in U.S. Patent Nos.5,681,380 to Nohr, et al. and 6,542,379 to Nohr, et al., which areincorporated herein in their entirety by reference thereto for allpurposes.

If desired, the composition may also be applied to a strip that issubsequently adhered or otherwise attached to the solid support. Forexample, the strip may contain a facestock material commonly employed inthe manufacture of labels, such as paper, polyester, polyethylene,polypropylene, polybutylene, polyamides, etc. An adhesive, such as apressure-sensitive adhesive, heat-activated adhesive, hot melt adhesive,etc., may be employed on one or more surfaces of the facestock materialto help adhere it to a surface of the solid support. Suitable examplesof pressure-sensitive adhesives include, for instance, acrylic-basedadhesives and elastomeric adhesives. In one embodiment, thepressure-sensitive adhesive is based on copolymers of acrylic acidesters (e.g., 2-ethyl hexyl acrylate) with polar co-monomers (e.g.,acrylic acid). The adhesive may have a thickness in the range of fromabout 0.1 to about 2 mils (2.5 to 50 microns). A release liner may alsobe employed that contacts the adhesive prior to use. The release linermay contain any of a variety of materials known to those of skill in theart, such as a silicone-coated paper or film substrate.

The exact quantity of a colorant employed in the present invention mayvary based on a variety of factors, including the sensitivity of thecolorant, the presence of other additives, the desired degree ofdetectability (e.g., with an unaided eye), the suspected concentrationof the microorganism, etc. In some cases, it is desirable to only detectthe presence of Candida at a pathogenic concentration. For example, aCandida concentration of about 1×10³ colony forming units (“CFU”) permilliliter of growth media or more, in some embodiments about 1×10⁵CFU/ml or more, in some embodiments about 1×10⁶ CFU/ml or more, and insome embodiments, about 1×10⁷CFU/ml or more may be consideredpathogenic. It should be understood that such concentrations maycorrelate to a liquid sample or a non-liquid sample (e.g., skin orobtained from skin) that is cultured in a growth media. Regardless, thecolorant may be employed in an amount sufficient to undergo a detectablecolor change in the presence of Candida at a desired concentration. Forinstance, the colorant may be applied at a concentration from about 0.1to about 100 milligrams per milliliter of carrier, in some embodimentsfrom about 0.5 to about 60 milligrams per milliliter of carrier, and insome embodiments, from about 1 to about 40 milligrams per milliliter ofcarrier. Likewise, the colorant may constitute from about 0.001 wt. % toabout 20 wt. %, in some embodiments from about 0.01 wt. % to about 10wt. %, and in some embodiments from about 0.1 wt. % to about 5 wt. % ofthe dry weight of the solid support.

The degree to which a colorant changes color may be determined eithervisually or using instrumentation. In one embodiment, color intensity ismeasured with an optical reader. The actual configuration and structureof the optical reader may generally vary as is readily understood bythose skilled in the art. Typically, the optical reader contains anillumination source that is capable of emitting electromagneticradiation and a detector that is capable of registering a signal (e.g.,transmitted or reflected light). The illumination source may be anydevice known in the art that is capable of providing electromagneticradiation, such as light in the visible or near-visible range (e.g.,infrared or ultraviolet light). For example, suitable illuminationsources that may be used in the present invention include, but are notlimited to, light emitting diodes (LED), flashlamps, cold-cathodefluorescent lamps, electroluminescent lamps, and so forth. Theillumination may be multiplexed and/or collimated. In some cases, theillumination may be pulsed to reduce any background interference.Further, illumination may be continuous or may combine continuous wave(CW) and pulsed illumination where multiple illumination beams aremultiplexed (e.g., a pulsed beam is multiplexed with a CW beam),permitting signal discrimination between a signal induced by the CWsource and a signal induced by the pulsed source. For example, in someembodiments, LEDs (e.g., aluminum gallium arsenide red diodes, galliumphosphide green diodes, gallium arsenide phosphide green diodes, orindium gallium nitride violet/blue/ultraviolet (UV) diodes) are used asthe pulsed illumination source. One commercially available example of asuitable UV LED excitation diode suitable for use in the presentinvention is Model NSHU55OE (Nichia Corporation), which emits 750 to1000 microwatts of optical power at a forward current of 10 milliamps(3.5-3.9 volts) into a beam with a full-width at half maximum of 10degrees, a peak wavelength of 370-375 nanometers, and a spectralhalf-width of 12 nanometers.

In some cases, the illumination source may provide diffuse illuminationto the colorant. For example, an array of multiple point light sources(e.g., LEDs) may simply be employed to provide relatively diffuseillumination. Another particularly desired illumination source that iscapable of providing diffuse illumination in a relatively inexpensivemanner is an electroluminescent (EL) device. An EL device is generally acapacitor structure that utilizes a luminescent material (e.g., phosphorparticles) sandwiched between electrodes, at least one of which istransparent to allow light to escape. Application of a voltage acrossthe electrodes generates a changing electric field within theluminescent material that causes it to emit light.

The detector may generally be any device known in the art that iscapable of sensing a signal. For instance, the detector may be anelectronic imaging detector that is configured for spatialdiscrimination. Some examples of such electronic imaging sensors includehigh speed, linear charge-coupled devices (CCD), charge-injectiondevices (CID), complementary-metal-oxide-semiconductor (CMOS) devices,and so forth. Such image detectors, for instance, are generallytwo-dimensional arrays of electronic light sensors, although linearimaging detectors (e.g., linear CCD detectors) that include a singleline of detector pixels or light sensors, such as, for example, thoseused for scanning images, may also be used. Each array includes a set ofknown, unique positions that may be referred to as “addresses.” Eachaddress in an image detector is occupied by a sensor that covers an area(e.g., an area typically shaped as a box or a rectangle). This area isgenerally referred to as a “pixel” or pixel area. A detector pixel, forinstance, may be a CCD, CID, or a CMOS sensor, or any other device orsensor that detects or measures light. The size of detector pixels mayvary widely, and may in some cases have a diameter or length as low as0.2 micrometers.

In other embodiments, the detector may be a light sensor that lacksspatial discrimination capabilities. For instance, examples of suchlight sensors may include photomultiplier devices, photodiodes, such asavalanche photodiodes or silicon photodiodes, and so forth. Siliconphotodiodes are sometimes advantageous in that they are inexpensive,sensitive, capable of high-speed operation (short risetime/highbandwidth), and easily integrated into most other semiconductortechnology and monolithic circuitry. In addition, silicon photodiodesare physically small, which enables them to be readily incorporated intovarious types of detection systems. If silicon photodiodes are used,then the wavelength range of the emitted signal may be within theirrange of sensitivity, which is 400 to 1100 nanometers.

Optical readers may generally employ any known detection technique,including, for instance, luminescence (e.g., fluorescence,phosphorescence, etc.), absorbance (e.g., fluorescent ornon-fluorescent), diffraction, etc. In one particular embodiment of thepresent, the optical reader measures color intensity as a function ofabsorbance. In one embodiment, absorbance readings are measured using amicroplate reader from Dynex Technologies of Chantilly, Va. (Model #MRX). In another embodiment, absorbance readings are measured using aconventional test known as “CIELAB”, which is discussed in Pocket Guideto Digital Printing by F. Cost, Delmar Publishers, Albany, N.Y. ISBN0-8273-7592-1 at pages 144 and 145. This method defines three variables,L*, a*, and b*, which correspond to three characteristics of a perceivedcolor based on the opponent theory of color perception. The threevariables have the following meaning:

L*=Lightness (or luminosity), ranging from 0 to 100, where 0=dark and100=light;

a*=Red/green axis, ranging approximately from −100 to 100; positivevalues are reddish and negative values are greenish; and

b*=Yellow/blue axis, ranging approximately from −100 to 100; positivevalues are yellowish and negative values are bluish.

Because CIELAB color space is somewhat visually uniform, a single numbermay be calculated that represents the difference between two colors asperceived by a human. This difference is termed ΔE and calculated bytaking the square root of the sum of the squares of the threedifferences (ΔL*, Δa*, and Δb*) between the two colors. In CIELAB colorspace, each ΔE unit is approximately equal to a “just noticeable”difference between two colors. CIELAB is therefore a good measure for anobjective device-independent color specification system that may be usedas a reference color space for the purpose of color management andexpression of changes in color. Using this test, color intensities (L*,a*, and b*) may thus be measured using, for instance, a handheldspectrophotometer from Minolta Co. Ltd. of Osaka, Japan (Model #CM2600d). This instrument utilizes the D18 geometry conforming to CIENo. 15, ISO 7724/1, ASTME1164 and JIS 28722-1982 (diffusedillumination/8-degree viewing system. The D65 light reflected by thespecimen surface at an angle of 8 degrees to the normal of the surfaceis received by the specimen-measuring optical system. Still anothersuitable optical reader is the reflectance spectrophotometer describedin U.S. Patent App. Pub. No. 2003/0119202 to Kaylor, et al., which isincorporated herein in its entirety by reference thereto for allpurposes. Likewise, transmission-mode detection systems may also be usedin the present invention.

The above-described screening techniques may be implemented in a varietyof ways in accordance with the present invention. For example, a solidsupport (e.g., wipe) may be utilized that contains a detection zone thatprovides any number of distinct detection regions (e.g., lines, dots,stripes, etc.) so that a user may better determine the presence ofCandida or other microorganisms within a test sample. Each region maycontain the same colorant, or may contain different colorants forreacting with different types of microorganisms. Referring to FIG. 1,one embodiment of the present invention is shown in which a solidsupport 80 is in the form of a wipe that employs a detection zone 82.For instance, the detection zone 82 may contain a colorant thatundergoes a color change in the presence of Candida albicans (e.g.,Phenol Red). When a dermal sample (e.g., skin) infected with Candidaalbicans contacts the wipe 80, the detection zone 82 undergoes a colorchange (FIG. 1B). However, when a dermal sample infected only withanother microorganism (e.g., S. aureus) contacts the wipe 80, thedetection zone 82 will remain substantially the same.

Although not required, an array of different colorants may also beemployed to enhance the ability to differentiate Candida from othermicroorganisms. The array provides a distinct spectral response (e.g.,pattern of colors) or “fingerprint” for Candida. For example, the arraymay provide a certain spectral response in the presence of Candidaalbicans or other Candida species, but provide a completely differentspectral response in the presence of S. aureus, E. coli, or otherbacteria commonly associated with diaper rash. Detection of the spectralresponse provided by the array may thus allow for enhanceddifferentiation Candida and other microorganisms.

When employed, the array may contain a plurality of discrete regions(referred to as “addresses”) spaced apart in a predetermined pattern.The addresses contain a colorant capable of exhibiting a color change inthe presence of a particular microorganism. The selection of colorantsfor the array is not critical to the present invention so long as thearray produces a distinct spectral response. The individual arrayaddresses may be configured in a variety of ways to accomplish thispurpose. In one particular embodiment, individual array addresses maycontain colorants that each exhibits a distinct spectral response in thepresence of Candida and another microorganism (e.g., S. aureus or E.coli). For instance, a first array address may contain a phthaleincolorant (e.g., Phenol Red) and a second array address may contain aN-phenolate betaine colorant (e.g., Reichardt's dye). Of course, thespectral distinction between individual array addresses need not alwaysbe provided by the use of different colorants. For example, the samecolorants may be used in individual array addresses, but at a differentconcentration so as to produce a different spectral response. Certainaddresses may likewise contain the same colorant at the sameconcentration, so long as the array as whole is capable of producing adistinct spectral response.

Apart from the composition of the individual array addresses, a varietyof other aspects of the array may be selectively controlled to enhanceits ability to provide a distinct spectral response. One factor thatinfluences the ability of the array to produce a distinct spectralresponse is the number of array addresses employed. Namely, a greaternumber of individual array addresses may enhance the degree that thespectral response varies for different microorganisms. However, anoverly large number of addresses can also lead to difficulty in visuallydifferentiating between spectral responses. Thus, in most embodiments ofthe present invention, the array contains from 2 to 50 array addresses,in some embodiments from 3 to about 40 array addresses, and in someembodiments, from 4 to 20 array addresses. The number of addressesemployed in the array will ultimately depend, at least in part, on thenature of the selected colorants. That is, if the selected colorantshave a similar color change in the presence of a microorganism, a largernumber of addresses may be needed to provide the desired spectralresponse.

Another aspect of the array that may influence its ability to provide adistinctive spectral response is the pattern (e.g., size, spacing,alignment, etc.) of the individual array addresses. The individual arrayaddresses may possess a size effective to permit visual observationwithout unduly increasing the size of the solid support. The size of theaddresses may, for example, range from about 0.01 to about 100millimeters, in some embodiments from about 0.1 to about 50 millimeters,and in some embodiments, from about 1 to about 20 millimeters. The shapeof the addresses may also enhance visual observation of the spectralresponse. For example, the addresses may be in the form of stripes,bands, dots, or any other geometric shape. The addresses may also bespaced apart a certain distance to provide a more visible spectralresponse. The spacing between two or more individual array addressesmay, for example, range from about 0.01 to about 100 millimeters, insome embodiments from about 0.1 to about 50 millimeters, and in someembodiments, from about 1 to about 20 millimeters. The overall patternof the array may take on virtually any desired appearance.

Referring to FIG. 2A, one embodiment of the present invention is shownin which a solid support 180 is in the form of a wipe that employs anarray 181 containing a plurality of addresses 183, each of whichincludes a colorant. For example, a set of first addresses 183 a mayinclude colorants that undergo a color change in the presence of Candidaalbicans (e.g., Phenol Red) and a set of second addresses 183 b mayinclude colorants that undergo a color change in the presence of S.aureus or E. coli (e.g., Reichardt's dye). When a dermal sample (e.g.,skin) infected with Candida albicans contacts the wipe 180, the firstset of addresses 183 a undergo a color change, while the second set ofaddresses 183 b remains substantially the same or undergo only a faintcolor change (FIG. 2B). When a dermal sample infected with S. aureus orE. coli contacts the wipe 180, the second set of addresses 183 b undergoa color change, while the first set of addresses 183 a remainssubstantially the same or undergo only a faint color change (FIG. 2C).

Regardless, the spectral response of the colorant(s) may provideinformation about the presence of Candida or other microorganism towhich it is exposed. If desired, the response of the test colorant(s)(or array of colorants) may be compared to a control colorant (or arrayof colorants) formed in a manner that is the same or similar to the testcolorant(s) with respect to microorganism responsiveness. The comparisonmay be made visually or with the aid of an instrument. Multiple controlcolorants may likewise be employed that correspond to different types ofmicroorganisms at a certain concentration. Upon comparison, themicroorganism may be identified by selecting the control colorant havinga spectral response that is the same or substantially similar to theresponse of the test colorant, and then correlating the selected controlto a particular microorganism or class of microorganisms.

As a result of the present invention, it has been discovered that thepresence of Candida or other microorganism may be readily detectedthrough the use of a colorant that undergoes a detectable color change.The color change is rapid and may be detected within a relatively shortperiod of time. For example, the change may occur in about 20 minutes orless, in some embodiments about 10 minutes or less, in some embodimentsabout 5 minutes or less, in some embodiments about 3 minutes or less,and in some embodiments, from about 10 seconds to about 2 minutes. Inthis manner, the colorant may provide a “real-time” indication of thepresence or absence of Candida or other microorganism. Such a “realtime” indication may alert a user or caregiver to apply a treatmentcomposition (e.g., anti-fungal) to the infected area and/or to seek theadvice of a medical professional. On the other hand, the lack of a colorchange may provide the user or caregiver with an assurance that the areais free of infection and sufficiently cleaned.

The present invention may be better understood with reference to thefollowing examples.

EXAMPLES Materials Employed

All reagents and solvents were obtained from Sigma-Aldrich ChemicalCompany, Inc. of St. Louis, Mo. unless otherwise noted and were usedwithout further purification. The microorganisms used in the study were:

1. Gram Negative (Viable)

-   -   Escherichia coli (ATCC #8739) (E. coli)    -   Psuedomonas aeruginosa (ATCC #9027) (P. aeruginosa)    -   Klebsiella pneumoniae (ATCC #4352) (K. pneumoniae)    -   Proteus mirabilis (ATCC #7002) (P. mirabilis)

2. Gram Positive (Viable)

-   -   Staphylococcus aureus (ATCC #6538) (S. aureus)    -   Lactobacillus acidophilus (ATCC #11975) (L. acidophilus)    -   Staphylococcus epidermidis (ATCC #12228) (S. epidermidis)    -   Bacillus subtilis (ATCC #19659) (B. subtills)    -   Enterococcus faecalis (ATCC #29212) (E. faecalis)

3. Yeast (Viable)

-   -   Candida albicans (ATCC #10231) (C. albicans)

The colorants used in the study are listed with their molecularstructure in Table 1:

TABLE 1 Exemplary Colorants and Their Corresponding Structure ColorantStructure 4-[(1-Methyl-4(1H)- pyridinylidene)ethylidene]-2,5-cyclohexadien-1-one hydrate

3-Ethyl-2-(2-hydroxy-1- propenyl)benzothiazolium chloride

1-Docosyl-4-(4-hydroxystyryl)- pyridinium bromide

N,N-Dimethylindoaniline

Quinalizarin

Merocyanine 540

Eriochrome Blue SE

Phenol Red

Nile Blue A

1-(4-Hydroxyphenyl)-2,4,6- triphenylpyridinium hydroxide inner salthydrate

Azomethine-H monosodium salt hydrate

Indingo carmine

Methylene Violet

Eriochrome Blue Black B

Methylene Blue

Nile Red

Trypan Blue

Safranin O

Crystal Violet

Methyl Orange

Chrome Azurol S

Leucocrystal violet

Leucomalachite Green

Leuco xylene cyanole FF

4,5-Dihydroxy-1,3- benzenedisulfonic acid disodium salt monohydrate

5-Cyano-2-[3-(5-cyano-1,3- diethyl-1,3-dihydro-2H-benzimidazol-2-ylidene)-1- propenyl]-1-ethyl-3-(4- sulfobutyl)-1H-benzimidazolium hydroxide inner salt

Acid Green 25

Bathophenanthrolinedisulfonic acid disodium salt trihydrate

Carminic Acid

Celestine Blue

Hematoxylin

Bromophenol Blue

Bromothymol blue

Rose Bengal

Universal indicator 0-5 Not available Universal indicator 3-10 Notavailable Alizarin Complexone

Alizarin Red S

Purpurin

Alizarin

Emodin

Amino-4-hydroxyanthraquinone

Nuclear Fast Red

Chlorophenol Red

Remazol Brilliant Blue R

Procion Blue HB

Phenolphthalein

Ninhydrin

Nitro blue tetrazolium

Orcein

Celestine blue

Tetra Methyl-para-phenylene diamine (TMPD)

5,10,15,20- Tetrakis(pentafluorophenyl)- porphyrin iron(III) chloride

Example 1

Various colorants were tested for their ability to undergo a colorchange in the presence of S. aureus, E. coli, and C. albicansmicroorganisms. The colorants tested were Reichardt's dye,1-Docosyl-4-(4-hydroxystyryl)pyridinium bromide,3-Ethyl-2-(2-hydroxy-1-propenyl)-benzothiazolium chloride,4-[(1-Methyl-4(1H)-pyridinylidene)ethylidene]-2,5-cyclohexadien-1-onehydrate, N,N-Dimethylindoaniline, Quinalizarin, Merocyanine 540,Eriochrome® Blue SE (Plasmocorinth B), Phenol Red, Nile Blue A,1-(4-Hydroxyphenyl)-2,4,6-triphenylpyridinium hydroxide inner salthydrate, Azomethine-H monosodium salt hydrate, Indigo Camine, MethyleneViolet, Eriochrome® Blue Black B, Biebrich scarlet-acid fuchsinsolution, Methylene Blue, Nile Red, Trypan Blue, Safranin O, CrystalViolet, Methyl Orange, and Chrome Azurol S.

Unless otherwise specified, the colorants were dissolved indimethylformamide (DMF). The colorant solutions were then pipetted onto15-cm filter paper (available from VWR International—Catalog No.28306-153) and allowed to dry. The filter paper was sectioned intoquadrants to test four (4) samples—i.e., S. aureus, E. coli, C.albicans, and sterile water. 100 microliters of 10⁷ CFU/mL of S. aureuswas pipetted onto the filter paper in one quadrant, 100 microliters of10⁷ CFU/mL of E. coli was pipetted onto the filter paper in a secondquadrant, 100 microliters of 10⁶ CFU/mL of C. albicans was pipetted ontothe filter paper in a third quadrant, and sterile water was pipetted inthe final quadrant. Color changes in the colorants were observed andrecorded for each of the samples tested. The color was recordedimmediately after the color change to inhibit the fading (or loss ofintensity) of the colors as the samples dried. Table 2 presents theobservations from the experiment.

TABLE 2 Observations of Colorant Color Change (Group 1) Initial ColorChange Color Color Color Change w/ Colorant Color w/S. aureus Changew/E. coli Change w/C. albicans sterile water Reichardt's dye BlueColorless Colorless Colorless No change 1-Docosyl-4-(4- Yellow Veryfaint Faint orange Faint orange Very faint orangehydroxystyryl)pyridinium orange bromide 3-Ethyl-2-(2-hydroxy-1- White/No change No change No change No change propenyl)benzothiazolium creamchloride, 4-[(1-Methyl-4(1H)- Bright No change No change No change Nochange pyridinylidene)ethylidene]-2,5- yellow cyclohexadien-1-onehydrate N,N-Dimethylindoaniline Grey Faint pink Very faint Very faint Nochange pink pink Quinalizarin Peach Yellow Faint purple Purple No changeMerocyanine 540 Hot Light purple Yellowish Deeper Reddish pink pink pinkyellowish pink Eriochrome Blue Deep Very faint Purple Deep purpleLighter pink with SE (Plasmocorinth B) pink purple dark pink border(dissolution) Phenol Red Yellow Yellow with Orange Deep Green withorange border red/orange orange border Nile Blue A Blue Pink Pink PinkNo change 1-(4-Hydroxyphenyl)-2,4,6- Yellow No change No change Nochange No change triphenylpyridinium hydroxide inner salt hydrateAzomethine-H monosodium Yellow/ Lighter with Lighter with Lighter withLighter with salt hydrate peach deeper border deeper deeper deeperborder (dissolution) border border (dissolution) (dissolution)(dissolution) Indigo Carmine Light Deeper light Deeper light Deeperlight Light blue with blue blue blue blue deeper border (dissolution)Methylene Violet Deep Deeper blue Deeper blue Deeper blue No changeblue/ violet Eriochrome ® Blue Black B Dark Lighter muddy Deep purpleDeep blue Darker muddy muddy purple purple purple Biebrich scarlet-acidfuchsin Bright Lighter with Lighter with Lighter with Lighter withsolution red deeper border deeper deeper deeper border (dissolution)border border (dissolution) (dissolution) (dissolution) Methylene Blue*Bright No change No change No change No change blue Nile Red BrightLight pink Light pink Light pink Faint pink purple Trypan Blue* Deep Nochange No change No change Faintly lighter with blue deeper border(dissolution) Safranin O Bright Yellowish with Yellowish YellowishPinkish with salmon salmon edge with salmon with salmon salmon edge edgeedge Crystal Violet Deep No change No change No change Faintly lighterwith blue deeper border (dissolution) Methyl Orange Bright Yellow YellowYellow Lighter orange orange with dark orange border (dissolution)Chrome Azurol S Pink Light orange Light yellow Brighter Light pink withwith dark with dark yellow with dark pink border orange border pinkborder dark pink border *Dissolved in water

With the exception of Methyl Orange, Nile Red, and Merocyanine 540, theobserved color change was almost immediate (1 to 2 minutes).

Example 2

Various colorants were tested for their ability to undergo a colorchange in the presence of S. aureus, E. coli, and C. albicansmicroorganisms. The colorants tested were Leucocrystal Violet,Leucomalachite Green, Leuco xylene cyanole FF,4,5-Dihydroxy-1,3-benzenedisulfonic acid disodium salt monohydrate,5-Cyano-2-[3-(5-cyano-1,3-diethyl-1,3-dihydro-2H-benzimidazol-2-ylidene)-1-propenyl]-1-ethyl-3-(4-sulfobutyl)-1H-benzimidazoliumhydroxide inner salt, Acid Green 25, Bathophenanthrolinedisulfonic aciddisodium salt trihydrate, Carminic Acid, Celestine Blue, Hematoxylin,Bromophenol Blue, Bromothymol Blue, Rose Bengal, Universal Indicator(0-5), and Universal Indicator (3-10). Unless otherwise specified, thecolorants were dissolved in dimethylformamide (DMF). The VWR filterpaper and colorants were prepared as described in Example 1. Table 3presents the observations from the experiment.

TABLE 3 Observations of Colorant Color Change (Group 2) Color ChangeInitial Color Color Color w/sterile Colorant Color Change w/S. aureusChange w/E. coli Change w/C. albicans water Leucocrystal violet WhiteBlue Blue Blue No change Leucomalachite Green White Green Green Green Nochange Leuco xylene cyanole FF White No change No change No change Nochange 4,5-Dihydroxy-1,3- White No change No change No change No changebenzenedisulfonic acid disodium salt monohydrate*5-Cyano-2-[3-(5-cyano-1,3- Bright Dark pink Dark purplish Dark Lighterpink diethyl-1,3-dihydro-2H- reddish pink greenish pink with dark pinkbenzimidazol-2-ylidene)-1- pink borderpropenyl]-1-ethyl-3-(4-sulfobutyl)- (dissolution) 1H-benzimidazoliumhydroxide inner salt Acid Green 25 Green Lighter green Lighter greenLighter green Lighter green with darker with darker with darker withdarker green border green border green border green border (dissolution)(dissolution) (dissolution) (dissolution) BathophenanthrolinedisulfonicWhite No change No change No change No change acid disodium salttrihydrate** Carminic Acid* Reddish Pale purple Purple Dark purpleLighter peach peach with darker peach border (dissolution) CelestineBlue Dark Blue Blue Blue Blue lavender Hematoxylin Pale No change Lightpurple Darker purple Pale yellow yellow with darker yellow border(dissolution) Bromophenol Blue Bright Dark blue Dark blue Dark blueLighter yellow Yellow with orangeish border (dissolution) BromothymolBlue Yellow Lighter Light green Darker green Very light yellow withyellow/whitish darker yellow with darker border yellow border RoseBengal Hot pink Darker pink Purplish pink Reddish pink White with darkpink border (dissolution) Universal Indicator (0-5) Yellowish YellowishYellowish Yellowish Lighter green green blue blue blue with dark greenborder (dissolution) Universal Indicator (3-10) Peach Pinkish OrangeishYellow Dark peach peach yellow *Dissolved in water **Dissolved in DMFand water

With the exception of Leucocrystal Violet, Leucomalachite Green, andLeuco xylene cyanole FF, the observed color change was almost immediate(1 to 2 minutes).

Example 3

Various colorants were tested for their ability to undergo a colorchange in the presence of S. aureus, E. coli, and C. albicansmicroorganisms. The colorants tested were Alizarin Complexone, AlizarinRed S, Purpurin, Alizarin, Emodin, Amino-4-hydroxyanthraquinone, NuclearFast Red, Chlorophenol Red, Remazol Brilliant Blue R, Procion Blue HB,Phenolphthalein, tetraphenylporphine, tetra-o-sulphonic acid, andNinhydrin. Unless otherwise specified, the colorants were dissolved indimethylformamide (DMF). The VWR filter paper and colorants wereprepared as described in Example 1. Table 4 presents the observationsfrom the experiment.

TABLE 4 Observations of Colorant Color Change (Group 3) Color ColorChange Color Change Color Change Change w/ Colorant Initial Color w/S.aureus w/E. coli w/C. albicans sterile water Alizarin Complexone YellowBrown Reddish purple Purple No change Alizarin Red S Yellow OrangeishPinkish purple Purple Lighter brown yellow with darker yellow border(dissolution) Purpurin Peachish Darker peachish Reddish pink Deeperreddish Yellowish orange orange pink peach Alizarin Butter yellow Nochange Light brown Purplish brown Greenish butter yellow Emodin YellowNo change Faint Greenish Deeper Greenish orange greenish orange yellowAmino-4- Pink Lighter pink Slightly lighter Faintly lighter Darker pinkhydroxyanthraquinone pink pink Nuclear Fast Red Reddish Deeper reddishYellowish pink Yellowish pink Dark pink pink pink Chlorophenol RedOrangeish Brown Deep reddish Deeper reddish Lighter yellow purple purpleorangeish yellow with darker border (dissolution) Remazol Brilliant BlueR Bright blue Lighter blue with Lighter blue with Lighter blue withLighter blue dark blue border dark blue border dark blue border withdark (dissolution) (dissolution) (dissolution) blue border (dissolution)Procion Blue HB Teal green No change No change Faintly darker Lighterteal teal with darker border (dissolution) Phenolphthalein White Nochange No change No change No change Tetraphenylporphine, Black Greywith Grey with Grey with Grey with tetra-o-sulphonic acid darker bordersdarker borders darker borders darker (dissolution) (dissolution)(dissolution) borders (dissolution) Ninhydrin White Deep purple Deeppurple Slightly lighter No change deep

The observed color change was almost immediate (1 to 2 minutes).

Example 4

The ability to rapidly detect various gram-positive and gram-negativemicroorganisms utilizing the colorants of Examples 1-3 was demonstrated.Additional colorants were also tested, including Plasmocorinth B, NitroBlue, Alizarin Complexone, Orcein, Tetra Methyl-para-phenylene diamine(TMPD), Nile Red, Eriochrome Blue Black B, Phenol Red, Alizarin Red S,Carminic Acid, Fe(III) C₃, Celestine Blue, Kovac's Reagent, ChromeAzurol S, Universal Indicator 3-10, Methyl Orange, Merocyanine 540, andIron III Chloride Porphyrin. The gram-positive microorganisms testedwere S. aureus, L. acidophilus, S. epidermidis, B. subtilis, and E.faecalis. The gram-negative microorganisms tested were E. coli, P.aeruginosa, K. pneumoniae, and P. mirabilis.

The colorant samples were prepared in a manner similar to Example 1.Unless otherwise specified, the colorants were dissolved indimethylformamide (DMF). Each of the colorant solutions were pipettedonto two separate pieces of VWR filter paper and allowed to dry. Onefilter paper sample with the dried colorant was sectioned into fiveapproximately equal sections to test the five gram-positivemicroorganisms. The other filter paper sample was sectioned intoquadrants to test the four gram negative microorganisms. 100 microlitersof 10⁷ CFU/mL of each microorganism sample was pipetted into theirrespective section of the sample of filter paper. Table 5 presents theobservations from the gram positive microorganisms and Table 6 presentsthe observations from the gram negative microorganisms.

TABLE 5 Color Change Observations for Gram Positive Microorganisms ColorColor Color Change w/ Color Change Color Change Change w/ Change w/Colorant Initial Color B. subtilis w/S. aureus w/S. epidermidis E.faecalis L. acidophilus Plasmocorinth B Deep pink Purplish Very faintDeeper pink Reddish pink Deeper pink purplish pink reddish pink NitroBlue Yellowish No change No change No change No change No changeTetrazolium white Alizarin Yellow Brownish Lighter Lighter LighterBrownish Complexone red brownish red brownish red brownish red yellowOrcein Muddy Light purple Lighter Darker muddy Darker Darker purplemuddy purple purple muddy muddy purple purple Tetra Methyl- BrightColorless Colorless Not tested Not tested Colorless para-phenylenelavender diamine (TMPD)* Nile Red Bright Light pink Light pink Lightpink Light pink Light pink purple Eriochrome Dark Muddy Bluish LighterDarker muddy Darker Darker Blue Black B purple purple muddy purplepurple muddy muddy purple purple Phenol Red Yellow Orange with Yellowwith Yellow with Yellow with Greenish yellowish orange orange borderorange yellow with center border border orange border Alizarin Red SYellow Brownish Light brown Light brown Light brown Light pink Greenishbrown Carminic Acid* Reddish Pale purple Paler purple Paler purplePurplish Yellowish peach peach peach Fe(III)C₃ White No change No changeNot tested Not tested No change Celestine Blue Dark Blue Blue Blue BlueBlue lavender Kovac's Pale yellow White with White with White with Whitewith White with Reagent greenish greenish greenish center greenishgreenish center and center and and yellow center and center and yellowyellow border border yellow brown border border border Chrome Azurol SPink Pale yellow Light orange Light yellowish Light orange Light redwith reddish with dark orange with with dark with dark border orangedark orange orange red border border border border Universal PeachLighter Lighter peach Lighter peach Lighter Red Indicator 3-10 peachwith with yellow with yellow peach yellow center center center MethylOrange Bright Yellow Yellow Yellow Yellow Yellow orange Merocyanine Hotpink Light purple Light purple Light purple Light purple Light purple540 Iron III Chloride Light Darker Darker Darker mustard Darker DarkerPorphyrin* mustard mustard mustard yellow mustard mustard yellow yellowyellow yellow yellow *Dissolved in water

TABLE 6 Color Change Observations for Gram Negative Microorganisms ColorChange w/ Color Change Color Change w/ Color Change w/ Colorant InitialColor E. coli w/P. aeruginosa K. pneumoniae P. mirabilis Plasmocorinth BDeep pink Light purple Deep blue Deep reddish pink Deep reddish pinkNitro blue Yellowish No change No change No change No change tetrazoliumwhite Alizarin Yellow Purple Deeper purple Brownish purple PurpleComplexone Orcein Muddy Light purple Dark purple Brownish purple Darkerbrownish purple purple Tetra Methyl- Bright Colorless Dark purpleColorless Colorless para-phenylene lavender diamine (TMPD)* Nile RedBright Light pink Light pink Light pink Light pink purple EriochromeBlue Dark Muddy Bluish purple Dark blue Darker purple Darker purpleBlack B purple Phenol Red Yellow Orange Dark red/orange Yellow withOrange orange border Alizarin Red S Yellow Brownish purple Deep reddishLight brownish Deep reddish purple purple purple Carminic Acid* ReddishBlueish purple Dark purple Paler Bluish Purple peach purple Fe(III)C₃White No change No change Not tested No change Celestine Blue Dark BlueBlue Blue Blue lavender Kovac's Pale yellow White with White with Whitewith White with Reagent greenish center greenish center greenish centergreenish center and yellow and yellow and yellow border and yellowborder border border Chrome Azurol S Pink Greenish yellow Bright yellowGreenish yellow Greenish yellow with dark pink with dark pink with darkpink with dark pink border border border border Universal Peach Lighterpeach Light green Darker peach with Lighter peach Indicator 3-10 withyellow yellow center with yellow center center Methyl Orange BrightYellow Yellow Yellow Orange/ orange yellow Merocyanine Hot pinkYellowish pink Yellowish pink Yellowish pink Yellowish pink 540 Iron IIIChloride Mustard Darker mustard Darker mustard Darker mustard Darkermustard Porphyrin* yellow yellow yellow yellow yellow *Dissolved inwater

With the exception of Methyl Orange, Nile Red, TetraMethyl-para-phenylene diamine (TMPD), and Merocyanine 540, the observedcolor change was also most immediate (1 to 2 minutes).

Example 5

Filter paper (available from VWR International) was treated withsolutions of Chrome Azurol, Alizarin Complexone, Plasmocorinth B, andPhenol Red (all dissolved in DMF). The samples were hung dry toevaporate the solvent. Solutions of C. albicans, E. coli, and S. aureuswere diluted in ten-fold dilutions using Trypticase Soybean Broth (TSB)media, and is some cases, sterile water, Concentrations ranged from 10⁸CFU/mL (stock solution) down to 10¹ CFU/mL for both E. coli and S.aureus, and 10⁷ CFU/mL (stock solution) down to 10¹ CFU/mL for C.albicans. TSB and water were used as control solutions. 100 μL aliquotsof each solution were applied to the samples. The color changes aresummarized in Tables 7-11.

TABLE 7 Response to Dilutions of C. albicans in TSB media Initial TSBDye Color 10⁶ CFU/ml 10⁵ CFU/ml 10⁴ CFU/ml 10³ CFU/ml 10² CFU/ml 10¹CFU/ml Control Phenol Red Bright orange Slightly Slightly SlightlySlightly Slightly Dark yellow darker darker darker darker darker orangeorange orange orange orange orange Plasmocorinth B Bright PurplishSlightly Slightly Slightly Slightly Slightly Dark pink blue darkerdarker darker darker darker purplish Purplish Purplish Purplish PurplishPurplish blue blue blue blue blue blue Alizarin Bright Brownish SlightlySlightly Slightly Slightly Slightly Dark Complexone yellow purple darkerdarker darker darker darker Brownish Brownish Brownish Brownish BrownishBrownish purple purple purple purple purple purple Chrome rose GreenishSlightly Slightly Slightly Slightly Slightly Yellowish Azurol yellowdarker darker darker darker darker green Greenish Greenish GreenishGreenish Greenish yellow yellow yellow yellow yellow

TABLE 8 Response to Dilutions of S. aureus in TSB media Initial 10⁸CFU/ml TSB Dye Color (undiluted) 10⁷ CFU/ml 10⁶ CFU/ml 10⁵ CFU/ml 10⁴CFU/ml 10³ CFU/ml 10² CFU/ml Control Phenol Red Bright Bright orangeSlightly Slightly Slightly Slightly Slightly Dark yellow yellow darkerdarker darker darker darker orange orange orange orange orange orangePlasmocorinth Bright Bright Purplish Slightly Slightly Slightly SlightlySlightly Dark B pink purplish blue darker darker darker darker darkerpurplish pink Purplish Purplish Purplish Purplish Purplish blue blueblue blue blue blue Alizarin Bright Light Brownish Slightly SlightlySlightly Slightly Slightly dark Complexone yellow brown purple darkerdarker darker darker darker Brownish Brownish Brownish Brownish BrownishBrownish purple purple purple purple purple purple Chrome rose BrownishGreenish Slightly Slightly Slightly Slightly Slightly Yellowish Azurolyellow yellow darker darker darker darker darker green Greenish GreenishGreenish Greenish Greenish yellow yellow yellow yellow yellow

TABLE 9 Response to Dilutions of S. aureus in water 10⁷ CFU/ml DyeInitial Color (in H₂O) Water Control Phenol Red Bright yellow N/A Lightyellow Plasmocorinth B Bright pink Bright pink Light pink AlizarinBright yellow Pale yellow Pale yellow Complexone Chrome Azurol roseGreenish Light red-pink red-pink

TABLE 10 Response to Dilutions of E. coli in TSB media Initial 10⁸CFU/ml TSB Dye Color (undiluted) 10⁷ CFU/ml 10⁶ CFU/ml 10⁵ CFU/ml 10⁴CFU/ml 10³ CFU/ml 10² CFU/ml Control Phenol Red Bright Light orangeSlightly Slightly Slightly Slightly Slightly Dark yellow orange darkerdarker darker darker darker orange orange orange orange orange orangePlasmocorinth Bright Pinkish Purplish Slightly Slightly SlightlySlightly Slightly Dark B pink purple blue darker darker darker darkerdarker purplish Purplish Purplish Purplish Purplish Purplish blue blueblue blue blue blue Alizarin Bright Purplish Brownish Slightly SlightlySlightly Slightly Slightly dark Complexone yellow brown purple darkerdarker darker darker darker Brownish Brownish Brownish Brownish BrownishBrownish purple purple purple purple purple purple Chrome rose Lightgreen Greenish Slightly Slightly Slightly Slightly Slightly YellowishAzurol yellow darker darker darker darker darker green Greenish GreenishGreenish Greenish Greenish yellow yellow yellow yellow yellow

TABLE 11 Response to Dilutions of E. coli in water 10⁷ CFU/ml DyeInitial Color (in H₂O) Water Control Phenol Red Bright yellow Orangishyellow Light yellow Plasmocorinth B Bright pink Bright pink Light pinkAlizarin Bright yellow Brownish yellow Pale yellow Complexone ChromeAzurol rose Dark green Light red-pink

Thus, a color change was observed for the microorganisms that wasdifferent than the media alone, although the difference was somewhatmore subtle for the dilute solutions. Without intending to be limited intheory, it is believed that the more subtle difference for the dilutesolutions was due in part to the lack of time given to themicroorganisms to condition the media (the experiment was conductedshortly after dilution). In contrast, the stock solutions containedmicroorganisms that had been in the media for 24 hours.

Example 6

Ink jet formulations including Phenol Red and Eriochrome Blue Black Bwere made according to the following recipe:

Component Wt. % Ethylene Glycol 6.0 Glycerol 3.0 PEG 200 6.01,3-Propanediol 3.0 Surfynol ® 465 nonionic surfactant 0.1 Colorant +Water 81.9

The formulations were filled into cartridges using standardmethodologies. HUGGIES Supreme® scented baby wipes (basis weight of 75grams per square meter) were printed with the inks using a Display MakerSeries XII/62 color span printer. Exposure of the printed materials to10⁶ CFU/mL of C. albicans resulted in a color change from yellow tobright orange for phenol red and from purple to dark blue for EriochromeBlue Black B. Exposure to 10⁷ CFU/mL E. coli did not produce anoticeable color change with the ink jet printed materials.

Example 7

A formulation was made that included approximately 1 wt. % Phenol Red inwater. The formulation was applied to a HUGGIES Supreme® scented babywipe using a plastic dropper. The wipe was then exposed to variousamounts of C. albicans (from 10⁷ to 10³ CFU/mL). A color change fromyellow to orange was observable for each of the tested concentrations.

Example 8

A formulation was made that included approximately 1 wt. % Chlorophenol

Red in water. The formulation was applied to a HUGGIES Supreme® scentedbaby wipe using a plastic dropper. The wipe was then exposed to variousamounts of C. albicans (from 10⁷ to 10³ CFU/mL). A color change fromyellow to bright pink was observable for each of the testedconcentrations.

While the invention has been described in detail with respect to thespecific embodiments thereof, it will be appreciated that those skilledin the art, upon attaining an understanding of the foregoing, mayreadily conceive of alterations to, variations of, and equivalents tothese embodiments. Accordingly, the scope of the present inventionshould be assessed as that of the appended claims and any equivalentsthereto.

1. A wipe for detecting a secondary infection associated with diaperrash, the wipe comprising a phthalein compound that produces a firstspectral response in the presence of Candida albicans, a second spectralresponse in the presence of Staphylococcus aureus, and a third spectralresponse in the presence of Escherichia coil, wherein the first spectralresponse is visually distinctive from the second and third spectralresponses, wherein the wipe contains a nonwoven web and wherein thenonwoven web contains absorbent fibers, synthetic thermoplastic fibers,or a combination thereof.
 2. The wipe of claim 1, wherein the phthaleincompound undergoes a color change at a pH of about 6.6.
 3. The wipe ofclaim 1, wherein the phthalein compound is Phenol Red.
 4. The wipe ofclaim 1, wherein the first spectral response is produced at a Candidaalbicans concentration of about 1×10³ or more colony forming units permilliliter.
 5. The wipe of claim 1, wherein the first spectral responseis produced at a Candida albicans concentration of about 1×10⁶ or morecolony forming units per milliliter.
 6. The wipe of claim 1, wherein thewipe contains a wet wipe solution.
 7. The wipe of claim 1, wherein thesecond spectral response is a color that is substantially the same asthe color of the phthalein compound prior to contact with Staphylococcusaureus.
 8. The wipe of claim 1, wherein the third spectral response is acolor that is substantially the same as the color of the phthaleincompound prior to contact with Escherichia coll.
 9. The wipe of claim 1,wherein the phthalein compound is Phenol Red, Chlorophenol Red,Metacresol Purple, Cresol Red, Pyrocatecol Violet, Xylenol Blue, XylenolOrange, Mordant Blue 3,3,4,5,6-tetrabromophenolsulfonephthalein,Bromoxylenol Blue, Bromophenol Blue, Bromochiorophenol Blue, BromocresolPurple, Bromocresol Green, Bromothymol Blue, Thymol Blue, BromocresolPurple, thymolphthalein, or a combination thereof.